I have a Colt 7.62x39 flatop upper that I purchased from a friend about ten years ago. The deal was too good to pass up at the time. After sitting in the corner of a safe for all those years, I decided to make it into a complete rifle, for shooting our problem feral hogs.
I'm guessing the bore diameter is .310, but in all the components that were included in the deal, all the bullets and loaded ammo were .308 bullets! The guy I bought all this stuff from, has passed...so no info is available there.
I just called Colt, and the first guy(FNG!) said they didn't make the upper in that cal., but someone next to him straightened him out! But, nobody would tell me, for liability reasons, what the bore diameter was for those rifles! They just said to "use the ammunition it was designed for!" What a DIKHED! That's exactly what I want to do! I just prefer to load my own!
What I'm trying to avoid, is the hassle of slugging the barrel!
So, if anyone knows for certain, or could provide a link to documentation of what bore diameter Colt used for their rifles, it certainly would be a big help!
Thanks in advance!
1D